FW-Ⅱ型轴流泵短期辅助抗体内血栓形成性能评价

Short term in vivo thrombosis evaluation of FW- Ⅱ axial blood pump for left ventricular assist

目的对优化设计FW-Ⅱ轴流泵短期辅助的抗血栓性能进行评价，为后期临床应用提供依据。方法5只60—70坛成年小尾寒羊，建立心室-泵-降主动脉旁路循环模型。FW-Ⅱ轴流泵辅助循环2周，分别在术前和置入泵术后1、2、3、7、10、14天抽取静脉血，应用流式细胞仪检测AnnexinV，CD41／61及CD14量化外周血中活化血小板及白细胞-血小板聚集；检测不同转速下血小板活化及白细胞-血小板聚集体。实验结束后观察轴流泵各组成部分有无血栓形成，取材观察心、脑、脾、肾大体和镜下病理表现。结果同术前相比较，置入轴流泵术后实验动物血小板活化及白细胞-血小板聚集体形成显著增加，第2天达到高峰，7天内维持较高水平，后逐渐降低，但术后14天仍高于术前水平。泵转速8000转／min时活化血小板和白细胞-血小板聚集体数最低。实验结束后拆分泵，轴流泵轴根部有少量血栓形成，叶轮、泵管及前、后导叶无血栓形成，心、脑、脾、肾等主要脏器大体和镜下观察均无血栓形成及缺血梗死表现。结论FW-Ⅱ型泵抗血栓性能良好，可用于短期循环辅助。特定转速下血小板活化和白细胞-小板聚集体值达到最低。

Objective To evaluate in vivo antithrombosis property of optimized FW-Ⅱ axial blood pump and provides evidence for future clinical use. Methods A left ventricle-pump-descending aorta bypass model was established in five healthy sheep （60 -70 kg） and the circulation of these sheep was assisted by FW-Ⅱ axial blood pump for 2 weeks. In preoperative and postoperative day 1, 2, 3,7,10 and 14, blood was drawn from the jugular vein to examine platelet activation and leukocyte-platelet aggregation respectively quantified with Annexin V, CD41/61 and CD14-PE by flow cytometry assays. Immediately after termination of the experiment, FW-Ⅱaxial blood pumps were explanted and each part was inspected for thrombus formation. Macroscopic and histological examinations were checked on heart, brain, kidney and spleen, respectively for thrombosis. Results Compared with preoperative baseline, the number of platelet activation and leukoeyte-platelct aggregation reached a peak at postoperative day 2, it retained a high level within 7 days, then gradually decreased, but was still higher than preoperative level at dayl4. According to rotating speed, the number of platelet activation and platelet-leukocyte aggregation were lowest at the speed of 8000 r/min Minus thrombus were found in the front and rear hub of the pump rotor, and there was no thrombus at other components （flow straighter, impeller and pump housing）. There were no isebemia and infarction evidences in macroscopic and histological examination of the heart, brain, kidney and spleen. Conclusion FW- Ⅱ axial blood pump can be used to assist left ventricular circulation for 2 weeks with a satisfactory antithrombosis property. The level of platelet activation and leukocyte-platelet aggregation can be reduced to a lowest level at an optimized pump rotating speed.